But how do you do that??? I don’t want it to be a permanent solution either but I am no engineer and haven’t the slightest clue how to get “all safety grounds at the same potential”…
Another buzz issue
Hi All, I recently updated my preamp to a Marantz AV7706. The Marantz has a 2 prong plug and after extensive trial and error have determined the hum must be a grounding issue. I have separate amps on all channels (a total of 4 amps with 3-prong plugs and a Marantz, 6 channel amp powering 3 pair of overhead fronts, sides and overhead rears for (ATMOS) configuration that, like the preamp, has a 2 prong plug. I don’t want to put cheater plugs on ALL of my 3 prong plugs so was wondering if/how it’s possible to “ground” - or convert - the 2 prong plugs to 3 prong? FWIW - I have a dedicated circuit for the HT/sound system, almost everything is plugged into a Furman AC “conditioner” and all plugged into the same circuit. There are NO coax runs. I’m sure there is another thread on this topic somewhere but am looking for guidance. Also, all the interconnects are in shielded, RCA (my 4 old Hafler 9300’s don’t take XLR). To rule out the cables I put in some old AQ shielded cables with no luck. I will also mention that there are a few auxiliary components (subwoofer, Amazon cube and and Apple TV that are plugged into a Panamax which is plugged into the same outlet/circuit - I just don’t have any more outlets available on the Furman. I have tried to troubleshoot this for over a year and have had 2 installers come out with no luck. At first I thought there was a problem with the Marantz but swapped it out for a new one (same model) so doubt that’s the issue.
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The goal is to get all safety grounds at the same potential. Defeating the safety grounds altogether is not really a solution, although it can be a useful diagnostic tool.
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Success!!! Thanks for the suggestions. The solution turned out as follows: I had all my amps plugged into a Furman surge protector and the TV and some other ancillary products plugged into a Panamax, both of which were plugged into a dedicated circuit outlet. I eliminated the Panamax and bought a 12 gauge power tap at Home Depot. I plugged this into the Furman and gave me enough outlets to plug everything into the Furman. I then put cheater plugs on ALL 3 prong devices and unplugged the Panamax. That did the trick! Definitely trail and error was involved but this turned out to be the solution! Why the Hell manufactures make ungrounded products - I’m looking at you Marantz! - I’ll never know. Either all components should be grounded or not! Anyway, after over a year the problem was solved and my system never sounded better as the buzz masked all the fine detail and “air” around the instruments! I’m not happy I have high-dollar aftermarket power cords interfaced to a .99 cent cheater plug but oh well. I figure if something electrical goes wrong it will hit the Furman as opposed to the (now ungrounded) equipment plugged into it… |
Thanks for the suggestions. When this problem first occurred I detached the coax (from a TV antennae which I don’t use anymore) and didn’t solve it. I then put cheater plugs on all 3 prong outlets. No luck. I then put RCA “dummy” plugs into everything on the pre-amp not used. I then put RF ferrite clamps on damn near everything. It was then I called an electrician to have a separate, dedicated line put in and had him check the ground outside the house. I’ve used this electrician many times over the years and he is really good and understood my issue so spent a lot of time testing all the electrical. I then had a CEDIA certified installer come out to essentially “rebuild” the system one component at a time. He couldn’t pinpoint the issue but suspected EMI/RF and suggested I use shielded RCA cable. So…I sent all my RCA cables back to the manufacturer to have shielded. No luck and the sound field “collapsed”. They told me this could happen so I have subsequently had them sent back to be “un-shielded”. So, those are the steps taken over the last year. I will say there seem to be days it’s worse and some days better. I will try some of the suggestions here but I have thrown so much time and money into this I almost want to throw in the towel and just live with it. In addition to the suggestions here - some of which I have not tried - I ordered the “faraday” fabric which I posted before. This won’t be in until the end of April though. But is was only $30 so what the Hell… I don’t know I technically adept enough to want to try the suggestion you had Steve about stripping the wire and attaching it to the preamp. My luck I’d have a bad result. That said, I will try several of these steps over the weekend - specifically turning off all the circuits except for the system and changing out where the subwoofer is plugged in. Currently the sub is plugged into a Panamax (which is plugged into the Furman). I had to do it this way because the sun power cable does t reach the Furman and the Panamax power cable doesn’t reach the wall outlet. I’m thinking a heavy duty extension cord - like for power tools you find at Home Depot - and try using that to extend to the Panamax from the outlet. Anyway, thx for the suggestions and I’ll report back. |
@whiterockman - The problem may be due to mixing isolated components and grounded components. For example...
So you might want to try this little experiment
Like you I spent a long time trying to resolve this problem until I read about NAIM products
Hope you find a solution Regards - Steve |
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Thanks. I haven’t tried turning off power to everything in the house - except that circuit - but did have an electrician out to look everything over. And to clarify, it does sound more like a 60 cycle “hum” than a “buzz”. I appreciate the info! As far as amplifier placement, I’m kind of limited there, though I did consider - thinking it could have been an issue - getting some EMI/RF blocking fabric to put on the shelves that the amps sit on… it’s on Amazon for $70. Block EMF RFID EMI RF Shielding Conductive Copper Nickel Fabric for Smart Meter RF Blocking Plaid Ripstop Type Military Grade 197"x43" inch https://a.co/d/0avEBWV |
If you hear a buzz instead of a hum the problem may be induced noise instead of a ground loop. Try turning all the other circuits in your home off as a quick experiment. It could also be a result of the amplifier transformers being too close to your other gear. You don’t want to ground 2 prong devices. The lack of grounding is keeping them from being part of the problem, nor do you want to use a cheater plut. First issue is to narrow down your problem. Disconnect all inputs from your processor, and put it and all your amps on the same Furman conditioner. See if the hum still occurs. Then start turning amps off. Despite the fire department recommendation, you CAN extend a Furman conditioner with a pure power strip that has a built in breaker, like the one below. The reason fire safety people are concerned about daisy chaining power strips is that many strips and power cords are not fused and easily overloaded. The unit I show you below is 100% safe to extend a Furman power conditioner. Just don’t use a cheap, unfused/unprotected power cable in the middle.
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I recommend contacting Black Lion Audio and see which power conditioner they would recommend. I use the PG-2 with great results. https://www.blacklionaudio.com/product-category/power-conditioners/ |
